Implements a high-pass filter that compensates for attenuation in the audio data. Speech signals have an attenuation
(a decrease in intensity of a signal) of 20 dB/dec. It increases the relative magnitude of the higher frequencies
with respect to the lower frequencies.

The Preemphasizer takes a Dataobject that usually represents audio data as input, and outputs the same Dataobject, but with preemphasis applied. For each value X[i] in the input Data object X, the following formula is
applied to obtain the output Data object Y:

Y[i] = X[i] - (X[i-1] * preemphasisFactor)

where 'i' denotes time.

The preemphasis factor has a value defined by the field PROP_PREEMPHASIS_FACTOR of 0.97. A common value for
this factor is something around 0.97.

Other Dataobjects are passed along unchanged through this Preemphasizer.

The Preemphasizer emphasizes the high frequency components, because they usually contain much less energy than lower
frequency components, even though they are still important for speech recognition. It is a high-pass filter because
it allows the high frequency components to "pass through", while weakening or filtering out the low frequency
components.